When machining cylindrical components, such as the valves of a steam turbine, in a field situation, several factors become important such as ease of set-up, adjacent equipment, rigidity of set-up, and ease of use. Previously, a fixed machine which sits on a platform mounted outside the valve extended into the valve for machining purposes. Although quite suitable for its intended purpose, this has several drawbacks, such as the need for a rigid platform in front of the valve to support a large bulky machine, as well as possible interference with adjacent machinery, and difficulty of set-up.
A tool which can mount within the valve or other cylindrical member is advantageous. U.S. Pat. No. 4,678,379 issued on July 7, 1987, to Sunday, which patent is assigned to the present assignee and incorporated herein by reference, discloses an apparatus for machining a valve seat. The apparatus is designed to machine a stop valve seat ring while the valve is still connected to the turbine. A pair of spiders with adjustable arms fit within the valve and cooperate with a shaft rotatably supported therein. A motor is attached to one of the spiders, the shaft including a tool support which holds and is capable of moving a single-edge cutting tool axially to machine the seat ring. While this device can satisfactorily machine a valve seat ring, it has a limited-use potential. A multi-purpose machine for boring and facing valves and cylinders, having versatility and ease of use, is desired. Moreover, a device which can be inserted within cylinders and valves encompassing a wide range of diameters would be advantageous.